Leo the Mathematician (English Wikipedia)

For a detailed discussion of Leo's telegraph and his automata, see Leone Montagnini (2002), "Leone il Matematico, un anello mancante nella storia della scienza", Archived 2013-10-17 at the Wayback Machine Studi sull'Oriente Cristiano, 6 (2), 89–108.

doi.org (Global: 2^nd place; English: 2^nd place)

Browning, Robert (1964). "Byzantine Scholarship". Past and Present (28): 7–8. doi:10.1093/past/28.1.3.
According to Joseph Genesius and Theophanes Continuatus between 829 and 833; Symeon the Logothete makes the caliph al-Mutasim and puts the invitation after the Islamic conquest of Amorium in the fall of 838, cf. Treadgold, Warren T. (1979). "The Chronological Accuracy of the Chronicle of Symeon the Logothete for the Years 813–845". Dumbarton Oaks Papers. 33: 162. doi:10.2307/1291437. JSTOR 1291437.
Treadgold, Warren T. (1979). "The Revival of Byzantine Learning and the Revival of the Byzantine State". The American Historical Review. 84 (5). American Historical Association: 1245–1266 [p. 1259]. doi:10.2307/1861467. JSTOR 1861467.

Trkulja J., Lees C. Armenians in Constantinople, in: Εγκυκλοπαίδεια Μείζονος Ελληνισμού, Κωνσταντινούπολη, 2008

According to Joseph Genesius and Theophanes Continuatus between 829 and 833; Symeon the Logothete makes the caliph al-Mutasim and puts the invitation after the Islamic conquest of Amorium in the fall of 838, cf. Treadgold, Warren T. (1979). "The Chronological Accuracy of the Chronicle of Symeon the Logothete for the Years 813–845". Dumbarton Oaks Papers. 33: 162. doi:10.2307/1291437. JSTOR 1291437.
Treadgold, Warren T. (1979). "The Revival of Byzantine Learning and the Revival of the Byzantine State". The American Historical Review. 84 (5). American Historical Association: 1245–1266 [p. 1259]. doi:10.2307/1861467. JSTOR 1861467.

For a detailed discussion of Leo's telegraph and his automata, see Leone Montagnini (2002), "Leone il Matematico, un anello mancante nella storia della scienza", Archived 2013-10-17 at the Wayback Machine Studi sull'Oriente Cristiano, 6 (2), 89–108.